I will be honest with you..... a lot of these places may be uncomfortable with you photographing the items they have worked hard to display so they can be sold. This is their art and I like to respect that. However, I am not above putting my phone on "silent" and exploring corners in the back, out of the way. (PS I definitely don't recommend pulling out your large DSLR for this sort of thing. All of the images I show here are iPhone photos.)

I do feel better if I buy something and then ask if I can photograph. I try to do this as often as is financially possible and is what I did when I was at the Brooklyn Flea Market last year. I bought one of these baseballs and then asked if could photograph the box of balls. He was fine with that and appreciated that I asked first.

Stores that offer vintage items are a great place to shop for things to use in floral and still life setups. This can also be part of the "treasure hunting" fun.

Julia Cameron in her book "The Artist's Way" recommends taking an "artist date" with yourself once a week. Even if you don't photograph, simply observing and taking in the details of the displays can be enough to stimulate ideas. Visual "eye candy" is sometimes all you need.

I love your suggestions for renewing our visual sense. I found myself in a junk shop the other day in Waimea, HI. It was filled with glass floats, bottles and Asian blue and white ware. I was thinking that I couldn't fit anything else into my house--but wish that I'd thought to photograph...next time!